The first thing that came to mind was the Roud Folk Song Index, a database of 250,000 songs all researched and compiled by a former librarian in the 70s, as a labor of love (and scholarly dedication, I guess). And then Samuel Johnson's A Dictionary of the English Language , a dictionary researched and written by a single man. He thought it would take three years, ended up taking nine years. All the more impressive fo…
https://www.neh.gov/humanities/2009/septemberoctober/feature...